A Woolly Mammoth’s Family Tree

These days, it's not uncommon for animals on various continents to be related. Animals are flown to be relocated in wildlife refuges, or even bred in-vitro in zoos. But what about woolly mammoths? Shouldn't their relations be restricted to the same landmass, since they weren't exactly capable of travel by sea or air? Apparently not, thanks to the help of the Bering Strait land bridge.

It may help to learn a little history of the lineage of the woolly mammoth. The animals are thought to have descended from elephants that migrated north from Africa – and needed to evolve to grow shaggy coats to keep warm. After the last ice age (about 10,000 years ago), the species became extinct.

Woolly Mammoths – World Travelers?

Scientists from McMaster University in Hamilton, Ontario studied DNA samples from the teeth and jawbones of over 150 woolly mammoths, in addition to examining data already on file. The data concluded that over the course of hundreds of thousands of years, the animals migrated back and forth between Alaska and Eurasia four or five times.

Based on the radiocarbon dating and the DNA samples, it appears that the first woolly mammoths migrated from Siberia to North America about 700,000 years ago. The relocated animals would then have evolved separately, and therefore had slightly different DNA over the course of several-hundred thousand more years.

The woolly mammoths with the slightly different genes made their way back to Siberia about 300,000 years ago, and became extinct around 8,000 BC. The North American mammoths, on the other hand, lived until about 10,000 years ago – around 6,000 BC.

Why the Siberian woolly mammoths died out before the mammoths in North America, we're not sure. It may be that climate, or even humans, could have had an impact. Do you think the cavemen were thinking about global warming as the ice melted and the woolly mammoths died out?

Resources:

http://news.nationalgeographic.com/news/2008/09/080904-woolly-mammoth.html

http://en.wikipedia.org/wiki/Woolly_Mammoth

http://www.nytimes.com/2008/09/09/science/09obmamm.html?partner=rssnyt&emc=rss

http://dsc.discovery.com/news/2008/09/04/woolly-mammoth-arctic-02.html

http://www.current-biology.com/content/article/abstract?uid=PIIS0960982208009706